As a promising lighting source for the future, the light emitting diode (LED) is a solid-state semiconductor device, which directly transfers electricity into light with such advantages as free pollution, high luminance, low power consumption, long service life and low working voltage. The GaN-based LED uses ITO as the P-type electrode chip in replacement of Ni/Au, which improves the luminance by 20%-30% compared with conventional electrode chip. Among many transparent electrodes (TCL), the ITO, CTO, InO and ZnO can improve the current spreading effects.
Patent Application No. CN200710091743.4 discloses a semiconductor light-emitting device with laminated transparent electrode, the disclosure of which is hereby incorporated by reference in its entirety. A transparent electrode is used as the current spreading bar to increase current spreading effect, eliminate electrode shading and increase light-emitting luminance. However, it can easily cause a high LED chip voltage (Vf). Therefore, Au metal or Au alloy is commonly used as the current spreading material in industry.